The present invention relates to a handy phone and more particularly to a handy phone capable of performing infrared communication with an external apparatus.
An infrared communication apparatus for performing communication within a preselected range by using infrared rays is conventional. Japanese Patent Laid-Open Publication No. 9-83443, for example, teaches an infrared communication apparatus including a receipt level determining section for determining the level of a signal come in through a receiving section, and a transmission output control section for controlling, based on the output of the receipt level determining section, a transmission output to be sent via a transmitting section. The function available with the infrared communication apparatus may be applied to a handy phone, as proposed in the past.
However, a conventional handy phone with an infrared communication capability has the following problems left unsolved. When the handy phone starts communicating with a peripheral apparatus, the former reports information received from the latter to the upper layer of firmware only after sending a station location command in all slots. On receiving this information, the upper layer informs the user of the phone of the presence/absence of a communicable station for the first time by using a visible message or sound. It therefore takes a long period of time for the user to see whether or not infrared communication can be held.
Assume that the distance between the infrared port of the phone station and that of the peripheral apparatus or the angle between the axes of the two ports is not adequate. Then, there may occur that the station location command does not reach the peripheral apparatus, that the station location command has reached the peripheral apparatus, but the phone does not detect any response, or that response data returned to the phone includes a bit error. In such a condition, the upper layer simply determines that a communicable station does not exist.
If a communicable station does not exist, as determined by the upper layer, the user of the phone recognizes the absence of such a station represented by a visible message or sound and must correct the relative position of the ports or the distance between the ports and again start communication all over again. Because the maximum number of slots available is sixteen and the maximum interval between consecutive slats is 500 ms, a long period of time is necessary for the setting condition to be transferred to the user. This renders the merits of infrared communication, which is cordless and not dependent on the configuration of a connector meaningless.
Technologies relating to the present invention are also disclosed in e.g., Japanese Patent Laid-Open Publication No. 2-228139 and Japanese Utility Model Laid-Open Publication No. 5-55683.